perturb

[ per-turb ]
/ pərˈtɜrb /

verb (used with object)

to disturb or disquiet greatly in mind; agitate.
to throw into great disorder; derange.
Astronomy. to cause perturbation in the orbit of (a celestial body).

Origin of perturb

1325–75; Middle English perturben (< Old French perturber) < Latin perturbāre to throw into confusion, equivalent to per- per- + turbāre to disturb; see turbid

Related forms

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for unperturbed

British Dictionary definitions for unperturbed (1 of 2)

unperturbed

/ (ˌʌnpəˈtɜːbd) /

adjective

not disturbed or troubledunperturbed by the prospect of a fight

British Dictionary definitions for unperturbed (2 of 2)

perturb

/ (pəˈtɜːb) /

verb (tr; often passive)

to disturb the composure of; trouble
to throw into disorder
physics astronomy to cause (a planet, electron, etc) to undergo a perturbation

Derived Forms

perturbable, adjectiveperturbably, adverbperturbing, adjectiveperturbingly, adverb

Word Origin for perturb

C14: from Old French pertourber, from Latin perturbāre to confuse, from per- (intensive) + turbāre to agitate, from turba confusion
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012